I had a similar problem with my first Garmin, an eTrex Vista, about 3 years ago. I was on a trip to Arizona and spent the night in Albequerque on my way. I got up very early, before my family, and did some geocaching before returning to awaken them and get on the road. My GPSr worked fine. Once on the road, I turned it on and it was working fine for a while. I pulled off I-40 to grab a cache hidden in some lava rocks along a frontage road when the unit lost a lock on the satellites and wouldn't recover. Fortunately, it had pointed me to within 10 feet of the cache before it lost the lock, so I was able to score the find. Unfortunately, my last one of the trip, except for some virtuals that I could locate from the cache descriptions, because the unit would never lock onto the satellites again.
When I returned home, I called Garmin and they walked me through several steps to try to solve the problem, including downloading an update to the software. Nothing worked, so they said to send it to them for repair. I asked how much it would cost, because the unit was 14 months old and the warranty was 1 year. They said not to worry. So I mailed it to them and about a week later I received a brand new unit back! And no charge! That unit worked well until I replaced it about a year later with a eTrex Vista C. As far as I know, it still works well (I gave it to my son, who had expressed an interest in geocaching but has never gotten started for some reason!)
Anyway, it was the oddest thing. I'll check out the link you provided. It may come in handy sometime. By the way, although I initially began to worry about the quality of the Garmin units, the way Garmin treated me has definitely made me a repeat customer. They were courteous, helpful, and took care of my problem at no extra cost to me! And my eTrex Vista C is nearly two years old and has operated without a hitch the whole time. -- ORR
"Wildness is a necessity." -- John Muir
"When you go to hide a geocache, think of the reason you are bringing people to that spot. If the only reason is for the geocache, then find a better spot." – briansnat